Encryption Workshop 3.0
Encryption Workshop includes file and folder encryption and decryption tool. Currently nine strong symmetrical block ciphers are implemented: BLOWFISH, GOST, RC 4, DES, Skipjack, TWOFISH, TEA and XOR. Any type of file can be encrypted/decrypted, not only ZIP files. If working with ZIP archives you might want to consider using encryption rather than password protection - it is much safer. Of course, if you are really concerned about privacy of your data, there's nothing to stop you from protecting your archives with password and encrypting them.
Please be aware that many implementations of encryption algorithms exist on the market. While they all employ the same ideas they don't necessarily have to be binary compatible. Therefore, it may happen that files encrypted by Encryption Workshop will not be decrypted by other software or vice versa.